Hi mudders.. some of you will be aware that I've put a tonne of work into my 80 series that I inherited from my late father. It's a 94 petrol/lpg variant with 152,000kms mileage.
I've had a series of issues that have been resolved and a tonne of parts replaced. I think it's important to list these, so you know what's been replaced and what hasnt. But before I do, the issue I'm having is a slightly lumpy idle in neutral or park. You can see the tacho needle moving up and down ever so slightly. It revs cleanly and smoothly. If I use the throttle lock to bump it up from 650rpm to 850rpm, it's still there. I've also noticed that when coming to a stop at a set of lights, it feels like the revs dip a bit too low at around 500rpm. It doesn't stall, but doesn't feel right, and the car never used to do this in the past. Apart from this, the car drives fine, otherwise.
2 things I think might be worth mentioning..
1. My car does not have a cold start idle. The revs do not flare to 1200rpm when cold and slowly come down. My idle is basically the same hot or cold.
2. the VAF (airflow meter) flap has a tiny bit of stiction when you initially push the flap. It still moves freely, but does not shut 100% either sometimes.
My questions are:
1. How much does the IACV control the idle after the vehicle is warm?
2. Given the flap of the VAF is not airtight, does what I explained above really matter?
Work completed:
New genuine idle air control valve (I've tried a second hand one and my original, all 3 behave the same)
New NGK spark plugs (yes, gap was checked)
New NGK blue ignition leads (I replaced these for the originals which had about 148,000km on them).
New genuine fuel pressure regulator
New genuine fan belts + ac pulley
New genuine vacuum hoses (not all, but any that looked flared or were easy to pull off)
New genuine Toyota fuel filter
New heavy duty brake booster, master cylinder and fluid flush
Engine oil and filter
Valve clearances checked, shimmed + new genuine rocker cover gasket and spark plug tube seals
New genuine oxygen sensor
Throttle position sensor checked and adjusted
New genuine distributor cap and rotor
New genuine exhaust gaskets, nuts and rubber cushion mounts
Engine timing and LPG mixture tune up with wideband sensor to check AFRs
Throttle body cleaned
On car injector clean (pressurized clean of cleaner straight into fuel rail)
New radiator + all hoses + cap + thermostat
New genuine Toyota heater control valve
New genuine Toyota engine coolant temp sensor
Power steering fluid flush and replacement
Transmission fluid replaced
New Japanese wheel bearings
New swivel hub seals, axle seals and gaskets
New genuine sway bar mount bushings
New Century heavy duty 4wd battery
Just had my 13 year old BFG KM2 muddies replaced with Yokohama Geolandar AT4 G018 all terrains in 285/75R16 yesterday, and wow.. what a difference to steering feel and noise! The heavy steering and howling are now a thing of the past!
Appreciate any comments or suggestions on the idle issue.
Cheers
Pete
I've had a series of issues that have been resolved and a tonne of parts replaced. I think it's important to list these, so you know what's been replaced and what hasnt. But before I do, the issue I'm having is a slightly lumpy idle in neutral or park. You can see the tacho needle moving up and down ever so slightly. It revs cleanly and smoothly. If I use the throttle lock to bump it up from 650rpm to 850rpm, it's still there. I've also noticed that when coming to a stop at a set of lights, it feels like the revs dip a bit too low at around 500rpm. It doesn't stall, but doesn't feel right, and the car never used to do this in the past. Apart from this, the car drives fine, otherwise.
2 things I think might be worth mentioning..
1. My car does not have a cold start idle. The revs do not flare to 1200rpm when cold and slowly come down. My idle is basically the same hot or cold.
2. the VAF (airflow meter) flap has a tiny bit of stiction when you initially push the flap. It still moves freely, but does not shut 100% either sometimes.
My questions are:
1. How much does the IACV control the idle after the vehicle is warm?
2. Given the flap of the VAF is not airtight, does what I explained above really matter?
Work completed:
New genuine idle air control valve (I've tried a second hand one and my original, all 3 behave the same)
New NGK spark plugs (yes, gap was checked)
New NGK blue ignition leads (I replaced these for the originals which had about 148,000km on them).
New genuine fuel pressure regulator
New genuine fan belts + ac pulley
New genuine vacuum hoses (not all, but any that looked flared or were easy to pull off)
New genuine Toyota fuel filter
New heavy duty brake booster, master cylinder and fluid flush
Engine oil and filter
Valve clearances checked, shimmed + new genuine rocker cover gasket and spark plug tube seals
New genuine oxygen sensor
Throttle position sensor checked and adjusted
New genuine distributor cap and rotor
New genuine exhaust gaskets, nuts and rubber cushion mounts
Engine timing and LPG mixture tune up with wideband sensor to check AFRs
Throttle body cleaned
On car injector clean (pressurized clean of cleaner straight into fuel rail)
New radiator + all hoses + cap + thermostat
New genuine Toyota heater control valve
New genuine Toyota engine coolant temp sensor
Power steering fluid flush and replacement
Transmission fluid replaced
New Japanese wheel bearings
New swivel hub seals, axle seals and gaskets
New genuine sway bar mount bushings
New Century heavy duty 4wd battery
Just had my 13 year old BFG KM2 muddies replaced with Yokohama Geolandar AT4 G018 all terrains in 285/75R16 yesterday, and wow.. what a difference to steering feel and noise! The heavy steering and howling are now a thing of the past!
Appreciate any comments or suggestions on the idle issue.
Cheers
Pete
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